Telegram-Kanaele als Quelle: Parser, Pipeline, UI-Checkbox, Validate-Endpoint

- Neuer source_type telegram_channel in models.py (Source + Incident)
- DB-Migration: include_telegram Spalte fuer incidents
- feeds/telegram_parser.py: Telethon-basierter Parser (analog RSS)
- Orchestrator: Telegram-Pipeline parallel zu RSS + WebSearch
- sources.py: POST /api/sources/telegram/validate Endpoint
- incidents.py: include_telegram in Create/Update/Response
- dashboard.html: Telegram-Checkbox + Filter-Option
- app.js: FormData, EditModal, SourceStats, TypeLabels
- config.py: TELEGRAM_API_ID, API_HASH, SESSION_PATH
- requirements.txt: telethon hinzugefuegt

src/routers/sources.py

@@ -87,6 +87,7 @@ async def get_source_stats(
     stats = {
         "rss_feed": {"count": 0, "articles": 0},
         "web_source": {"count": 0, "articles": 0},
+        "telegram_channel": {"count": 0, "articles": 0},
         "excluded": {"count": 0, "articles": 0},
     }
     for row in rows:
@@ -516,6 +517,32 @@ async def delete_source(
     await db.commit()
 
 
+
+
+@router.post("/telegram/validate")
+async def validate_telegram_channel(
+    data: dict,
+    current_user: dict = Depends(get_current_user),
+):
+    """Prueft ob ein Telegram-Kanal erreichbar ist und gibt Kanalinfo zurueck."""
+    channel_id = data.get("channel_id", "").strip()
+    if not channel_id:
+        raise HTTPException(status_code=400, detail="channel_id ist erforderlich")
+
+    try:
+        from feeds.telegram_parser import TelegramParser
+        parser = TelegramParser()
+        result = await parser.validate_channel(channel_id)
+        if result:
+            return result
+        raise HTTPException(status_code=404, detail="Kanal nicht erreichbar oder nicht gefunden")
+    except HTTPException:
+        raise
+    except Exception as e:
+        logger.error("Telegram-Validierung fehlgeschlagen: %s", e, exc_info=True)
+        raise HTTPException(status_code=500, detail="Telegram-Validierung fehlgeschlagen")
+
+
 @router.post("/refresh-counts")
 async def trigger_refresh_counts(
     current_user: dict = Depends(get_current_user),